Trump allies say emails unlawfully gained

An organisation set up for US President Donald Trump's transition to the White House says the special counsel investigating allegations of Russian meddling in the 2016 election obtained tens of thousands of emails unlawfully.

Kory Langhofer, counsel to the transition team known as Trump for America, Inc. (TFA), wrote a letter to congressional committees to say Special Counsel Robert Mueller's team had improperly received the emails from the General Services Administration (GSA), a government agency.

Career staff members at the agency "unlawfully produced TFA's private materials, including privileged communications, to the Special Counsel's Office," according to the letter, a copy of which was seen by Reuters. It said the materials included "tens of thousands of emails."

Trump's transition team used facilities of the GSA, which helps manage the US government bureaucracy, in the period between the Republican's November presidential election victory and his inauguration in January.

The Trump team's accusation adds to the growing friction between the president's supporters and Mueller's office as it investigates whether Russia interfered in the election and if Trump or anyone on his team colluded with Moscow.

Asked for comment, White House spokeswoman Sarah Sanders said: "We continue to cooperate fully with the special counsel and expect this process to wrap up soon."

The special counsel's office waved off the transition team's complaint.

"When we have obtained emails in the course of our ongoing criminal investigation, we have secured either the account owner's consent or appropriate criminal process," said Peter Carr, spokesman for the special counsel's office.

Trump has loudly declared Mueller's effort a waste of time. "There is absolutely no collusion. That has been proven," Trump told reporters on Friday.

Langhofer argued that, while such transition teams are involved in executive functions, they are considered private, non-profit organisations whose records are private and not subject to presidential records laws.